The Grim Reaper will cast a spell to your Senior Sim, that will become a Senior sim by aging them up and then the Grim Reaper will vanish. The Grim Reaper will go out of the house. He will usually start to appear when your Senior Sim's Life Duration Circle turns red.

Your (Senior) Sims' house when they are in the last quarter of their life. Sometimes he can be found using your Sims objects, such as a Stereo, a Bookshelf, BBQ's, ect.